fixup! [stdlib] Update Codable.swift

Author: benrimmington

stdlib/public/core/Codable.swift

@@ -502,7 +502,9 @@ public struct KeyedEncodingContainer<K: CodingKey> :
   /// Creates a new instance with the given container.
   ///
   /// - parameter container: The container to hold.
-  public init(_ container: some KeyedEncodingContainerProtocol<Key>) {
+  public init<Container: KeyedEncodingContainerProtocol>(
+    _ container: Container
+  ) where Container.Key == Key {
     _box = container
   }
 
@@ -1465,7 +1467,9 @@ public struct KeyedDecodingContainer<K: CodingKey> :
   /// Creates a new instance with the given container.
   ///
   /// - parameter container: The container to hold.
-  public init(_ container: some KeyedDecodingContainerProtocol<Key>) {
+  public init<Container: KeyedDecodingContainerProtocol>(
+    _ container: Container
+  ) where Container.Key == Key {
     _box = container
   }